diff --git a/library/bignum_core.c b/library/bignum_core.c
index a99b3be2bb..b0ffa37d3c 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -33,7 +33,7 @@
 #include "bn_mul.h"
 #include "constant_time_internal.h"
 
-inline size_t mbedtls_mpi_core_clz(mbedtls_mpi_uint a)
+size_t mbedtls_mpi_core_clz(mbedtls_mpi_uint a)
 {
 #if defined(__has_builtin)
 #if __has_builtin(__builtin_clz)